While it's far off from being any sort of confirmation, a recently announced change coming to the PlayStation Now streaming service might be an indication that Red Dead Redemption 2 will be playable on PC at some point... Just not via a proper port of its own.

The PlayStation Now service is a subscription-based streaming library which allows subscribers access to a given number of PlayStation 3 titles on either their PlayStation 4 consoles or on a PC (with a dualshock controller hooked up). The service has a rather large and expansive library and subscribers are given access to all of the games - you don't need to buy them on top of paying subscription fees.
While this offers a legitimate way of playing PlayStation 3 exclusive releases without the PS3 console itself, many users who have accessed the PS Now library on PC often report dodgy performance. Very high-end internet connections, both in terms of speed and stability, are needed to stream the games decently, and even then the best you'll get is 30 FPS and dodgy controls with some limited functionality.
Red Dead Redemption is included in the PlayStation Now service, thus marking the game's debut on PC. This is a less than stellar way to play the game, however, it's the only way to go if you want to play Rockstar's Western epic on your PC.
Yesterday though, the PlayStation Now library was expanded with PlayStation 4 titles, none of which were available through the service previously. This move pushed said library past the 500 game mark, but more importantly, it holds much potential for the future and is relevant for Red Dead fans for two reasons. One good, the other bad.
First of all, based on the fact that Red Dead Redemption was made available through the service and that Rockstar and Sony have some kind of deal going on, Red Dead Redemption 2 will likely make its way to PS Now eventually, and thus it will be playable on PC. This is the good news.
The bad is that it could mean a proper PC port of the game will never arrive.
This deal the two companies have with one another is likely the reason why the previous title isn't coming to PC amid the hype for the sequel. With all the buzz around Red Dead Redemption 2, releasing a remastered version of the 2010 installment on PC would have made ludicrous amounts of money.
People are already pining for new Red Dead content, especially with the delay that was recently announced, and there really wouldn't be any better way to cope with waiting than by playing a graphically upgraded Red Dead Redemption running on PC.
However, the fact that PS Now is involved means that Red Dead Redemption will definitely never make it to PC as a proper port, and possibly Red Dead Redemption 2 neither.
The reason is simple - the moment an actual port is released, with keyboard, mouse and 4K support, graphical options and an uncapped framerate, everyone will buy and play that, and no-one would use the PS Now version. The Red Dead name has massive recognition and draw, and we suspect many a PS Now subscriber is currently only paying because of that particular game being available.
By having a monopoly on Red Dead games on PC, the appeal of the PlayStation Now service is boosted significantly. And while no details of the actual deal between Sony and Rockstar are publicly known beyond PlayStation 4 players getting early access to post-launch DLC, maybe it contains something about no proper PC port being released while the partnership is still running.
If that's the case, let's just hope it doesn't run forever.